This invention relates to a body-supporting device forming the seat and/or back rest of a chair, its purpose being to avoid sweating caused by the thermal insulation of the chair.
The term "chair" is used to cover all types of furniture intended for sitting thereon, such as vehicle seats in all kinds of vehicles, office chairs and domestic arm chairs. This should be born in mind, as the invention is described below as it would be applied to the driver's seat of a conventional vehicle.
Every driver who has driven a car in hot weather, for example during the summer holiday period, has certainly experienced great problems with the sweating that takes place from those parts of the body that bear upon the driver's seat. This is because the chair, upon the body surfaces in contact with the chair, acts as a thermal insulator substantially obstructing and reducing the capability of the body to emit heat by radiation. The consequence is that other parts of the body must contribute more to meet the requirements of the body to be cooled by heat radiation. To achieve this it is common to open one or more windows, which results in draughts and negative consequences for health and and has a very small positive influence. However, if the temperature in the car is high enough, the body cannot loose enough heat by radiation without sweating. In this case the sweating will be particularly noticeable where the body is in contact with the chair, as an effective barrier to vapor diffusion is formed between the body and the support surfaces of the chair, making evaporation more difficult and causing these parts of the chair to become wet with sweat, which sticks to shirts, trousers and other items of clothing and causes severe discomfort. This phenomenon occurs even if the seat covers are made of material that can "breathe", avoiding non-permeable material such as leather.
In order to avoid the above disadvantages a driver's seat incorporating ducts in which cold air is circulated by a pump connected to the chair has been proposed. It is true that the circulation of the cold air inside the chair makes an increase of the heat radiation of the body from those surfaces that are in contact with the chair possible, but in practical trials with this type of chair it was found that the solution was unusable: the test drivers found after driving a vehicle with a cooled chair for some hours that their backs had become so chilled that they were unable to rise from the chair without assistance. Accordingly, the chair in question had no future.